Bug #13558: Array#insert does not typecheck the position argument if it's the only argument

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: ruby 2.4.0p0 (2016-12-24 revision 57164) [x86_64-darwin16]
• Backport: 2.2: WONTFIX, 2.3: DONE, 2.4: DONE

[kke (Kimmo Lehto)]

rb_ary_insert does this:

if (argc == 1) return ary;

For Ruby this means:

> [].insert("foo") 
 => []
> [].insert(Exception.new)
 => []

I would expect this to raise a TypeError. The problem here is that if you forget the position argument, because perhaps you thought Array#insert would be an alias for Array#unshift, you get unexpected results and no errors.

If you try to insert two items it fails nicely:

> [].insert('foo', 'foo')
TypeError: no implicit conversion of String into Integer

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Closed

Applied in changeset trunk|r58693.

---

array.c: check position to insert

• array.c (rb_ary_insert): check position to insert even if no
  elements to be inserted. [ruby-core:81125] [Bug #13558]

[usa (Usaku NAKAMURA)]

• Backport changed from 2.2: UNKNOWN, 2.3: UNKNOWN, 2.4: UNKNOWN to 2.2: WONTFIX, 2.3: REQUIRED, 2.4: REQUIRED

[usa (Usaku NAKAMURA)]

• Backport changed from 2.2: WONTFIX, 2.3: REQUIRED, 2.4: REQUIRED to 2.2: WONTFIX, 2.3: DONE, 2.4: REQUIRED

ruby_2_3 r59238 merged revision(s) 58693.

[nagachika (Tomoyuki Chikanaga)]

• Backport changed from 2.2: WONTFIX, 2.3: DONE, 2.4: REQUIRED to 2.2: WONTFIX, 2.3: DONE, 2.4: DONE

ruby_2_4 r59398 merged revision(s) 58693.